Tube



FIG. 1 is a front perspective view of a tube, showing my new design;

FIG. 2 is a right side view thereof, the left side being a mirror image;

FIG. 3 is a front view thereof, the back view being a mirror image;

FIG. 4 is a bottom view thereof; and,

FIG. 5 is a top view thereof. 

The ornamental design for a tube, as shown and described. 